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At least 271 records · Page 15Linked to original sources
PubMed2006

Semibiological molecular machine with an implemented "AND" logic gate for regulation of protein folding.

A semibiological molecular machine with an implemented "AND" logic gate was developed, which was capable of controlling the folding process of proteins in response to ATP and light as input stimuli. The molecular design made use of a genetically engineered chaperonin GroEL bearing, at both entrance parts of its cylindrical cavity, cysteine residues, which were functionalized by an azobenzene derivative to construct photoresponsive mechanical gates (azo-GroEL). This engineered chaperonin trapped denatured green fluorescent protein (GFP(denat)) and prohibited its refolding. However, when hosting azo-GroEL detected ATP (input stimulus 1) and UV light (input stimulus 2) at the same time, it quickly released GFP(denat) to allow its refolding. In contrast, reception of either input stimulus 1 or 2 resulted in only very slow or no substantial refolding of GFP(denat). Implementation of such "AND" logic gate mechanisms in mechanically driven biomolecular systems is an important step toward the design of secured drug delivery systems.

Adenosine Triphosphatases↗
PubMed2002

Application of a sediment quality triad and different statistical approaches (Hasse diagrams and fuzzy logic) for the comparative evaluation of small streams.

In order to evaluate the ecotoxicological contamination of 12 aquatic sites in streams within the catchment area of the Neckar River, a sediment quality triad (SQT) approach was applied. In contrast to Chapman's original triad approach, not only sediments, but also surface waters were examined. In brief, to obtain a comprehensive insight into the potential ecotoxicological hazard, both acute toxicity and more specific effects such as mutagenic, genotoxic, teratogenic, dioxin- and estrogen-like responses were recorded. Different statistical methods (ranking, cluster analyses, Hasse diagram techniques, and fuzzy logic) for the evaluation and presentation of the SQT data were compared with respect to the needs of environmental decision-making. Results document advantages and disadvantages of the methods applied for the evaluation and classification of data within the complex data matrixes. The ranking procedure presented as well as the Hasse diagram technique seem to be suitable tools to elucidate the pattern of the ecotoxicological load. However, these classification methods require expert knowledge to interpret the ranking results with respect to decision-making in environmental sciences and policy. In contrast, fuzzy logic allows both to develop site-specific expert systems in order to assess the ecotoxicological burden and to give insight into the pattern of the contamination.

Animals↗
PubMed2006

Effects of belief and logic on syllogistic reasoning: Eye-movement evidence for selective processing models.

Studies of syllogistic reasoning have demonstrated a nonlogical tendency for people to endorse more believable conclusions than unbelievable ones. This belief bias effect is more dominant on invalid syllogisms than valid ones, giving rise to a logic by belief interaction. We report an experiment in which participants' eye movements were recorded in order to provide insights into the nature and time course of the reasoning processes associated with manipulations of conclusion validity and believability. Our main dependent measure was people's inspection times for syllogistic premises, and we tested predictions deriving from three contemporary mental-models accounts of the logic by belief interaction. Results supported recent "selective processing" theories of belief bias (e.g., Evans, 2000; Klauer, Musch, & Naumer, 2000), which assume that the believability of a conclusion biases model construction processes, rather than biasing the search for falsifying models (e.g., Oakhill & Johnson-Laird, 1985) or a response stage of reasoning arising from subjective uncertainty (e.g., Quayle & Ball, 2000). We conclude by suggesting that the eye-movement analyses in reasoning research may provide a useful adjunct to other process-tracing techniques such as verbal protocol analysis.

Culture↗
PubMed2000

Beyond dissociation logic: evidence for controlled and automatic influences in artificial grammar learning.

Evidence for unconscious learning has typically been based on dissociations between direct and indirect tests of learning. Because of some inherent problems with dissociation logic, we applied the logic of opposition to 2 artificial grammar learning experiments. In Experiment 1, participants were exposed to 2 different sets of letter strings, generated from 2 different grammars, and later rated test strings for grammaticality with either in-concert (rate grammatical strings consistent with either structure) or opposition (rate grammatical only strings from 1 of the structures) instructions. Manipulating response deadline affected controlled, but not automatic influences. In Experiment 2, after similar training, a source-monitoring test was administered from which the in-concert and opposition conditions were derived. The test indicated that varying the retention interval affected controlled, but not automatic, influences. The results are discussed in terms of awareness, knowledge representation, and metacognitive processing.

Adolescent↗
PubMed2002

Logic and human reasoning: an assessment of the deduction paradigm.

The study of deductive reasoning has been a major paradigm in psychology for approximately the past 40 years. Research has shown that people make many logical errors on such tasks and are strongly influenced by problem content and context. It is argued that this paradigm was developed in a context of logicist thinking that is now outmoded. Few reasoning researchers still believe that logic is an appropriate normative system for most human reasoning, let alone a model for describing the process of human reasoning, and many use the paradigm principally to study pragmatic and probabilistic processes. It is suggested that the methods used for studying reasoning be reviewed, especially the instructional context, which necessarily defines pragmatic influences as biases.

Cognition↗
PubMed2005

The phenogenetic logic of life.

For nearly a century we have understood that life works through genes, and so have had an elegant theory for general evolution. But this did not explain the kinds of traits that characterize organisms, nor how genes produce them. Advances in recent decades have opened the way for an understanding of the phenogenetic logic or relational principles of life, by which a few basic characteristics of genomes produce biological phenotypes through some basic developmental processes. This logic provides a general explanation of the nature and source of organismal design, and a powerful programme for research.

Animals↗
PubMed2006

Two coupled enzymes perform in parallel the 'AND' and 'InhibAND' logic gate operations.

The coupled activation of two enzymes: glucose dehydrogenase (GDH) and horseradish peroxidase (HRP), is used to construct the parallel-operating AND and InhibAND logic gates. The added substrates for the respective enzymes, glucose and H(2)O(2), act as the gate inputs, while the biocatalytically generated NADH and gluconic acid provide the output signals that follow the operations of the gates. The two gates are generated in the same vial, thus allowing the logic operations to take place in parallel, and the simultaneous readout of the functions of the gates.

Glucose 1-Dehydrogenase↗
PubMed2003

[Toward a more gentle psychiatry--to patients and understanding illness of affect logic].

Based on the disease- and human understanding of "affect logic" developed by the author, new ways to a "more gentle psychiatry" than usual up to now are shown. Over 18 years continuous experience with the pilot project "Soteria Bern"--predominantly milieu- and psychotherapeutic treatment of acute schizophrenia--are used as examples. In refurbishing normal psychiatric hospital wards meant for all types of patients, a much less violent therapeutic atmosphere was created through the introduction of "Soteria-Elements" as well. In toto it can be shown that a more gentle psychiatry can be realized without greater costs, if the interaction between feeling, thinking and behavior are more fully understood and observed. For this, the concept of "affect logic" delivers a theoretic basis that has been proven in practice.

Acute Disease↗
PubMed1989

Replication of trance logic using a modified experimental design: highly hypnotizable subjects in both real and simulator groups.

A potentially useful method for diagnosing the presence of hypnosis has been the comparison of hypnotic Ss and simulators. The present study attempted to replicate the hypnotic-simulator differentiation in regard to trance logic, as originally described by Orne (1959), using a modified design in which Ss in the 2 conditions were matched for hypnotizability scores. Orne's doubled person hallucination (DPH) suggestion was presented, and the results showed significant differences between the 2 treatment conditions in both DPHs and spontaneous transparency reports. One interesting case of DPH occurred in the simulator group with one S in whom a hypnotic-like state was self-induced. In contrast to the placid acceptance of DPH among Ss in the hypnotic condition, the experience was a confusing and mildly disturbing one for this S, who was not expecting any unusual perceptual experiences. Trance logic results from the "metasuggestion," experienced through participation in a formal induction procedure, that hypnosis entails new rules of experience and behavior.

Adolescent↗
PubMed1976

On Ho's "modern logic and schizophrenic thinking".

The purpose of this note is to point out that conclusions drawn in the title paper about the role of logic in the schizophrenia thought process are not reliable, since they are based on patients medicated with antipsychotic drugs. The substance of this note is drawn from the title paper and related literature. The principal conclusion is that Dr. Ho's deductions about the role of logic in schizophrenia follow only if one confuses psychiatric diagnosis with psychotic behavior.

Antipsychotic Agents↗
PubMed1997

The concept of affect logic: an integrative psycho-socio-biological approach to understanding and treatment of schizophrenia.

In this article, the psycho-socio-biologically integrative concept of affect-logic, and its relevance for a comprehensive understanding and therapy of schizophrenia, is briefly presented. This concept has been developed by the author over the past 20 years, on the basis of the literature, of clinical experience and his own research into long-term evolution, rehabilitation, effects of milieu-therapy, and nonlinear evolutionary dynamics of the illness. It postulates, basically, that fundamental affective states (or emotions, feelings, moods) are continuously and inseparably linked to all cognitive functioning (or "thinking" and "logic" in a broad sense), and that affects have essential organizing and integrating effects on cognition. Schizophrenia is understood as an altered mode of affective-cognitive interaction based, possibly, on disturbed (loosened) affective-cognitive connections. This hypothesis leads to: 1) an integrative psycho-socio-biological model of long-term evolution of the illness; 2) a new understanding of psychopathological core phenomena such as ambivalence, incoherence, and emotional flattening; 3) an innovative therapeutic approach based on an emotion-relaxing milieu and style of care; and 4) the hypothesis that schizophrenia could basically be an affective (and not a cognitive) disease, of another kind than mania or melancholia, however.

Affect↗
PubMedDate not supplied

Adaptive fuzzy logic restriction rules for error correction and safe stimulation patterns during functional electrical stimulation.

Adaptive restriction rules based on fuzzy logic have been developed to eliminate errors and to increase stimulation safety in the foot-drop correction application, specifically when using adaptive logic networks to provide a stimulation control signal based on neural activity recorded from peripheral sensory nerve branches. The fuzzy rules were designed to increase flexibility and offer easier customization, compared to earlier versions of restriction rules. The rules developed quantified the duration of swing and stance phases into states of accepting or rejecting new transitions, based on the cyclic nature of gait and statistics on the current gait patterns. The rules were easy to custom design for a specific application, using linguistic terms to model the actions of the rules. The rules were tested using pre-recorded gait data processed through a gait event detector and proved to reduce detection delay and the number of errors, compared to conventional rules.

Electric Stimulation Therapy↗
PubMedDate not supplied

A fuzzy logic based closed-loop control system for blood glucose level regulation in diabetics.

In this study, a closed-loop system to control the plasma glucose level in patients with diabetes mellitus type 1 is proposed. This control scheme is based on fuzzy logic control theory to maintain a normoglycaemic average of 4.5 mmol 1(-1) and the normal conditions for free plasma insulin concentration in severe initial state; in particular, when the diabetic patient is subjected to a glucose meal disturbance or fluctuations in the measured glucose level due to error in the measuring instrument. The proposed controller has demonstrated superiority over other conventional controlling therapies. While fuzzy logic controllers have shown promising results in many fields, a comparative study is presented with well-known conventional controllers such as Proportional-Integral-Derivative (PID) and continuous insulin infusion control strategies. The simulated results, for the proposed controller, are presented and discussed.

Adaptation, Physiological↗
PubMed2006

The logic of diagnosis: Peirce, literary narrative, and the history of present illness.

This essay presents a theoretical construct upon which to base a working--"pragmatic"--definition of the History of Present Illness (HPI). The major thesis of this essay is that analysis of both the logic of hypothesis formation and literary narrative--especially detective stories--facilitates understanding of the diagnostic process. The essay examines three elements necessary to a successful development of a patient's HPI: the logic of hypothesis formation, based upon the work of the philosopher-logician, Charles Sanders Peirce; the organization of knowledge in relation to structures of narrative; and the feedback necessary to the successful physician-interviewer. It concludes with a systematic description of the design of hypothesis formation within diagnoses.

Diagnosis↗
PubMed1997

A key for freshwater invertebrates using fuzzy logic.

MOTIVATION: This paper summarizes a biological key using a fuzzy logic expert system. This approach allows the user to make some errors, be uncertain about some answers and not answer questions if unsure, but have an opportunity to identify unknown specimens correctly. This approach was adopted in order to develop a 'forgiving' key for users with little or no prior knowledge of identification. The system was implemented using a multi-media expert system builder, 'Matcher', operating in a Microsoft Windows environment. RESULTS: The paper reports the design issues for a key to identify freshwater invertebrates to family level and describes the types of questions used within the key, the fuzzy inference engine, the structure of the system and the methodology adopted for testing it. Following this, an empirical test is reported of the hypothesis that a fuzzy logic expert system can improve identification accuracy for a sample of intended users. Finally, the discussion considers the practicalities of using such a system as an aid to organism identification.

Algorithms↗
PubMed1995

Arterial pressure control with isoflurane using fuzzy logic.

Arterial pressure is still one of the most important measures in estimating the required dose of inhaled anaesthetics. It is measured easily and reacts rapidly which makes it suitable as a variable for feedback control of depth of anaesthesia. Fuzzy logic, a novel approach to feedback control, was used to control arterial pressure in 10 patients during intraabdominal surgery by automatic adjustment of the concentration of isoflurane in fresh gas. During anaesthesia, fuzzy control periods of 45-min duration were alternated randomly with human control periods of equal duration. During the skin incision period (-3 to + 12 min) 48.2% of all fuzzy control pressure values were within +/- 10% of the desired mean arterial pressure compared with 40.4% of the human control values (P < 0.05). The corresponding values for the remainder of the operation were 78.3% and 83.2%, respectively. Thus fuzzy out-performed human control at skin incision, but was slightly inferior during the rest of the operation. We conclude that fuzzy logic is a promising new technique for control of isoflurane delivery during routine anaesthesia.

Adult↗
PubMed2005

Logic models as aids in managing health programs.

Logic models, which are graphic depictions of how programs are intended to operate, can be very useful devices for improving the management of health programs in two important ways. They can assist program managers to perform the core management activities of strategizing, designing, and leading other program participants in an integrated manner. Logic models also can assist managers in establishing and maintaining good program stakeholder relationships.

Decision Making, Organizational↗
PubMed1995

Symbiosis of nurse and machine through fuzzy logic: improved specificity of a neonatal pulse oximeter alarm.

This article describes the theoretical underpinnings that preceded the design of a new neonatal pulse oximeter alarm that differentiates true from false alarms based on an artificial intelligence theory called "fuzzy logic." The connection between the intuition and sense of advocacy gained through neonatal primary nursing and the application of fuzzy logic to solve the problem of false alarms--that is, the symbiosis between nurse and machine--are explained. Emphasis is placed throughout on the importance of involving nurses in the development of the technology for which they are responsible.

Decision Making↗